Self-storing material handling attachment for lift trucks

ABSTRACT

A self-storing material handling attachment having a material engaging device including a frame for removably mounting the same on a transport vehicle, including a plurality of support legs borne by the frame for movement relative to the frame between a retracted position permitting unrestricted operation of the vehicle and an extended position for supporting and storing the attachment independently of the vehicle.

United States Patent Thompson et a1.

[ Nov. 20, 1973 SELF-STORING MATERIAL HANDLING ATTACHMENT FOR LIFT TRUCKS Inventors: Norman D. Thompson; Charles R.

, QQ YQaIEsJLL Ie Liljequist, Salem, all of Greg.

Assignee: Towmotor Corporation, Cleveland,

v.QhiQ.

Filed: Dec. 23, 1971 Appl. No.: 211,393

US. Cl. 214/621, 294/67 DA Int. Cl. B661 9/00, B661 13/00 Field of Search 214/621, 730, 515, 214/131 A; 248/188.6, 439; 294/67 D, 67

DA, 67 DB, 67 BC References Cited UNITED STATES PATENTS 5/1972 Downey 214/621 3,606,053 9/1971 Whiteman 214/621 3,495,727 2/1970 Primary ExaminerRobert J. Spar Assistant Examiner-Kenneth Noland AttorneyLeonard Phillips et al.

[5 7 ABSTRACT A self-storing material handling attachment having a material engaging device including a frame for removably mounting the same on a transport vehicle, including a plurality of support legs borne by the frame for movement relative to the frame between a retracted position permitting unrestricted operation of the vehicle and an extended position for supporting and storing the attachment independently of the vehicle.

6 Claims, 7 Drawing Figures SELF-STORING MATERIAL HANDLING ATTACHMENT FOR LIFT TRUCKS BACKGROUND OF THE INVENTION The structure of the present invention :is .intended to permit the convenient storage of a material handling attachment after it has been removed from a lift truck. or other vehicle on which it is adapted to be mounted. In the past, one appraoch has been to provide a separate storage rack or stand for such a conventional material handling attachment. The lift truck or other mounting vehicle is moved into a position facing the storage rack and the material handling device is placed in a supported position upon the rack. The device is then disconnected from the mounting vehicle, freeing the latter for other duties.

Of course, such a procedure requires that a special rack be provided and placed where it is accessible to the mounting vehicle, thus using valuable storage space as well as increasing the owner's operating costs. The use of a storage rack also forces the operator of the mounting vehicle to journey to the one location where the storage rack is available, or to provide .several racks and to strategically place them for most convenient use.

SUMMARY OF THE INVENTION The present invention provides a material handling attachment including a self-contained apparatus making the attachment independent from special storage racks. Such apparatus is retractable and unobstrusive when the attachment is in use on a transport vehicle, but at the same time is quickly and simply positioned to support and store the attachment when the attachment is not needed on the transport vehicle.

Accordingly, it is an object of the present invention to provide a self-storing material handling attachment that is readily removable from a mounting vehicle and can be stored at any convenient location, without requiring a separate supporting stand or rack.

Another object is to provide such an attachment, which includes a frame having a multiplicity of supporting legs that are an integral part of the attachment so as to be continuously available for immediate use.

Another object of the present invention is to provide such an attachment in which the supporting legs can be locked in either an extended attachment supporting position, or in a retracted position providing unrestricted operation of the mounting vehicle.

Other objects and advantages of the present invention will become more readily apparent upon reference to the accompanying drawings and following description:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the attachment embodying the principles of the present invention shown in the self-supporting, storage position.

FIG. 2 is a front elevation and partial section of one of the pivotable support leg assemblies of the attachment of FIG. 1 showing the leg swung to a retracted position.

FIG. 3 is a view similar to FIG. 2 but showing the leg in its unlocked position.

FIG. 4 is a front elevation and partial section showing the support leg of FIGS. 2 and 3 in an extended, unlocked position.

FIG. 5 is a front elevation and partial section showing the support leg of FIG. 4 in its external locked attachment-supporting position.

FIG. 6 is a front perspective view of the attachment mounted on a lift truck, fragmentally indicated in dashed lines, with all supporting legs locked in their retracted positions.

FIG. 7 is a side elevation of the attachment of FIG. 6, with a load indicated in dashed lines.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, a material handling attachment embodying the principles of the present invention is generally indicated by the reference numeral 10. As .shown in FIG. 6, the attachment is adapted to be conveniently mountable on a lift truck 12, which has a mast l4 and fork-type carriage assembly 15 from which the forks have been removed.

The self-storing material handling attachment 10 has .a substantially vertical frame assembly 16, and supporting a beam 18 oriented transversely to the longitudinal axis of the lift truck 12. The ends of the beam individually retain a support and lift arm assembly 20 by means of pivots 25 journaled into yolks affixed to either end of beam 18. Each of the arm assemblies 20 includes a twist lock 22 on each of its ends as shown in FIG. 1. The mechanism for the cargo container twist locks are similar to that shown in U.S. Pat. No. 3,499,563 to J. E. Forry, et a1, and is designed to fit into the upper corner fittings of a standard cargo container 39. The standard container dimensions are set forth and the structure of the comer fittings and twist lock mechanism are described in publication MI-I5.l1962 entitled Specifications for Freight Containers of the United States of America Standards Institute.

A flared container corner guide 24 is dependently mounted on the rearward end of each lift arm assembly 20 nearest to the lift truck after installation. Asbest shown in FIG. 7, the entire lift frame 10 is removably mountable on the carriage assembly 15 of lift truck 12 by any suitable fastener device, not shown, such as a plurality of hook-type brackets or the like. Accordingly, the attachment can be mounted and dismounted from the operators station on the lift truck by proper manipulation of the usual hydraulic controls thereon after the hydraulic connections to the attachment have been removed.

The vertical frame assembly 16 is a generally rectangular configuration and is fabricated from relatively heavy steel box section beams. Two spaced substantially parallel, generally vertically-oriented box beams 26 and 28 form a pair of upright members thereof, while similar beams 30 and 32 form a pair of upper and lower cross-members of the frame, respectively. Corner gussets 33 welded between cross beam and uprights 26, 28, are used to provide additional strengthening members for the frame assembly 16.

As best shown in FIG. 6, the transverse beam 18 is joined to the vertical frame assembly 16, by arms 34 and diagonal frame brace members 35. The arms ex- .tend generally horizontally away from the vertical frame assembly 16 for a distance of somewhat more than half the width of a standard cargo container 39. Clearance space is thus provided between the vertical frame assembly 16 and the adjacent side of the cargo 7 container, as best seen in FIG. 7. The container is thus allowed to swing about pivots to a. limited degree without contacting the vertical frame, while said cons. tainer is being lifted and transported. Furthermore, the. single transverse beam and the relatively narrow vertical frame assembly afford excellent operator visibility and vehicle clearance when the lift truck is traveling without a load.

As best shown in FIGS. 1 and 6, attachment 10 further includes a pair of vertically-oriented, slidable legs 36 and 38 disposed along the bottom vertical portion of frame 16. The legs are of rectangular shape with downwardly depending flat foot members 40 that are generally horizontally-disposed, and further include strategically placed holes 42 in at least one side of the legs, to accept legloo'king pins 44, which lock the legs in either the extended or retracted position on the attachment. The legs move in a substantially upward and downward direction within brackets 46, which brackets are shaped to slidably receive the legs therein. Brackets 46 have strategically placed holes 48 correspondingly spaced relative to the leg holes 42 to accept the leg locking pins 44 when the legs are placed in their extended or retracted position.

The brackets46 are individually secured to vertical box beams 26 and 28 as by welding orthe like. The lock pin holes 42 and 48 are understood to be of a size to accept the hand-emplaced locking pins. The locking pins can include keeper-chain mechanisms 50, with one end of said mechanism attached to the pins and the other end attached to brackets 46 or vertical beams 26 and 28. The keeper chains serve to eliminate loss or misplac e ment of the pins 44. 4 r

Attachment 10 further includes a pair of forwardly disposed, pivotally-mounted legs 52 and 54, as best shown in FIGS. 1 and 6; The legs 52,54 may be drawn up into a generally horizontally-oriented lock-up position (FIGS. 2, 6) as would be observed'when the lift frame attachment 10 is mounted on the lift truck 12. The legs 52, 54 may also be dropped into an extended, attachment-supporting position as shown in FIGS. 1 and 5. i

The legs 52 and 54 are generally rectangularl shaped and have a downwardly depending generally horizontally disposed flat foot member 56 that is weldably attached to the legs lowermost extremity. The uppermost extremity of the leg has a generally rectangularly-shaped leg-locking end 58 (FIGS. 2-5) incorporating a cam roller 60 thereon, a lever arm portion 62, a slotted hole 64 and an enlarged leg pivot portion 66 that accommodates a leg pivot sleeve 68.

The leg pivot sleeve 68 is correspondingly-shaped to fit around the outer surface of the leg pivot portion 66, being shaped and sized to allow the leg to slidably travel within the sleeve for a predetermined distance. Said sleeve further includes a hole 70 for a leg pivot pin 72. The hole 70 limits the sleeve movement relative to the attachment, to a pivotal "motion. The slotted hole 64 in the leg provides's aid leg with both pivotalmovent'a'nd slidable movement ment relative to the attachm relative to the sleeve, 1' i I I A bracket assembly74 pr'ovides'a pivotal support mounting for the legs 52 and 5 4'to' the transverse beam 18, and is weldably attached to thelatter. Bracket assembly 74 includes apivotpiri hole 76 for mounting the pivot pin 72 there thr'ough', and also includes'in'teriorly formed notches 78 arid 80, shaped and sized to receive the correspondingly-shaped leg locking end 58 for locking; Legs in either agenerally horizontal or a generallyyertical; positiom I A cam surface 82 is disposed on the interior of assembly 74betwe en the notches to provide a smooth leg action when the leg being changed from one position tothe other; The leg slotted hole 64 is of a size to allow the legto slidably travel within the pivot sleeve for a distance sufficient for the leg locking end to be withdrawn from the bracket notch 78 or 80. The pivot sleeve guides the leg in this slidable travel, and also serves to reduce the pin load in bending by forcing the leg to assume a rigid upright position when it is supporting the load of the stored attachment 10.

Hydraulic jacks 84, having a head end 86 and a rod end 88, are provided for movement of legs 52 and 54 between their extended attachment-storing posin'ons and their retracted attachment-operating positions. The head ends86 are pivotally attached to the backing plate of bracket assembly 74 or to the transverse beam 18, while the movable rod ends are pivotally attached to'the lever arm portion 62 of the leg locking end, as can be seen in FIGS. 2, 3, 4 and S. The hydraulic fluid pressure for powering the jacks is provided by a hydraulic system (not shown) normally associated with fork lift trucks.

.Operation While the operation of the present invention is believed clearly apparent from the foregoing description, further amplification will subsequently be made in the following brief summary of such operation.

The attachment 10 of the present invention is disposed in FIG. 1 in its self-storage position prior to being mounted on-the carriage assembly 15 of the fork lift truck 12, as seen in F IG. 7. The lift truck is positioned behind the attachment 10. The method of mounting and fastening the attachment to the fork lift truckmast and carriage 15 may be similar to that shown and described in the above designated Forry et al patent. The existing hydraulic and electric circuits of known construction provided on the fork lift truck are connected by coupling the appropriate quick-disconnect fittings in the usual. manner.

After mounting and coupling the attachment 10 to the carriageassembly 15 of the lift truck 12, the carriage is elevated a short distance sufficiently to remove the attachment weight from the legs 36, 38, 52 and 54. The locking pins 44 of the rearwardly disposed slidable legs 36 and 38 are withdrawn from the bracket holes 48 and the leg holes 42, at which time the legs are raised manually and the locking pins are reinserted in the bracket holes 48 and the appropriate leg holes 42.

The forwardly disposed pivotally-mounted legs 52 and 54 are then moved hydraulically from the downwardly extended positions shown in FIG. 5 to the retracted positions shown in FIG. 2 by appropriate manipulation of the hydraulic control system normally associated with the fork lift truck.

During the previously described raising of the lift -itruck" carriage 15, the pivotally-mounted legs gravitationally drop in a generally vertically-oriented direction for the predetermined distance established by the lflllgthgDf-lh leg pivot pin slot 64. This action causes the leg locking end 58 to be withdrawn from the correspondingly-shaped notch 78 of the bracket assembly {74,"as seen in.FIG. 4. The legs 52 and 54 may then be moved from the position shown in FIG. 4 to that shown in FIG. 2 by actuating the lift truck hydraulic control system, which applies hydraulic fluid pressure to the head-end 86 of the jack members 84. This forces the jack rods 88 to move in an outward direction relative to the jacks 84. Since the jack rods are attached to the leg lever-arm 62 of the legs 52 and 54, the legs and their associated pivot sleeves 68 are forced to pivot about the pins 72. This causes the legs to be moved into a generally horizontally-oriented position as seen in FIG. 3.

The action of the leg cam rollers 60 on the bracket cam surfaces 82 provides a relatively frictionless guided leg movement between the various leg positions. Continued fluid pressure directed into the headend of the jacks 84 causes the leg locking ends 58 to enter the correspondingly shaped locking notches 80 in the brackets 74, thus locking the legs in the substantially horizontal position of FIG. 2.

To remove the attachment from the mast and carriage of a lift truck 12, the preceding operational sequence is reversed. The rearwardly disposed slidable legs 36 and 38 are moved from their retracted positions of FIG. 6 to their extended, attachment-supporting positions of FIG. 1 by elevating the lift truck carriage to allow space between the foot members 40 and the vehicle supporting surface. Pins 44 are withdrawn from the bracket holes 48 and leg holes 42. The legs 36 and 38 then slidably move in a downward direction due to the forces of gravity. The pins 44 are reinserted in the bracket holes 48 and the appropriate leg holes 42.

Hydraulic fluid pressure is directed to the rod end of the hydraulic jacks 84, causing the rod-ends 88 to retract into the jacks. Since the rod ends 88 are rotatably attached to the leg lever arms 62, the leg locking ends 58 are withdrawn from the bracket locking notches 80. FIG. 2 shows the leg 54 position prior to the initiating the leg unlocking action and FIG. 3 shows the leg to bracket relationship after the leg end is removed from said locking notch. Coincidental with the preceding leg movement, the legs slidably travel within the sleeves 68 on the pins 72 to the extent allowed by the slotted holes 64 in the legs. The natural forces of gravity, together with the aforementioned fluid pressure within jacks 84, cause the legs to rotatably move from the generally horizontal position of FIG. 3 to the vertically-oriented position of FIG. 4. The cam roller 60, bearing along the cam surface 82, serves to help control the speed of leg rotative movement and provides added guidance of the lag action. The legs assume the fully locked positions of FIG. 5, when the lift truck carriage 15 is lowered, causing the weight of the attachment 10 to rest on its supporting legs.

The quick-disconnect electrical and hydraulic fittings are disconnected. The mountings and fastening devices, for mounting the attachment 10 to the carriage 15 as previously mentioned, are disconnected. The lift truck is thus free to move away from the self-supported attachment and assume other duties normally associated with fork lift trucks.

Accordingly, a self-storing material handling attachment has been provided that is readily removable from a mounting vehicle, for storage at any convenient location without a separate supporting rack or stand. It is significant that the multiplicity of supporting legs are an integral part of the attachment, so as to be continuously available for immediate use.

While the invention has been described and shown with particular reference to the preferred embodiment, it will be apparent that variations might be possible that would fall within the scope of the present invention which is not intended to be limited, except as defined in the following claims.

What is claimed is:

l. A self-storing material handling attachment mountable on a transport vehicle comprising, material engaging means, frame means including an upright frame member for attachment directly to said transport vehicle, and a horizontally disposed transverse member rigidly supported on said frame member, said transverse member of said frame means supporting said engaging means and said upright member being removably mounted on a transport vehicle, and support means including a multiplicity of leg members home by said frame means for movement relative to the frame means between retracted positions permitting unrestricted operation of the vehicle and extended positions for supporting the attachment independently of the vehicle, wherein at least one of said leg members is slidably mounted on said upright frame member, and at least one of said leg members is pivotably mounted on said transverse member, and wherein said pivotal legs include a lower surface-engaging foot end, an upper locking end, and an extended intermediate portion connecting said ends, power means borne by said frame pivotally connected to each said pivotal leg adjacent its locking end for swinging the leg between a substantially vertically disposed frame supporting position and a substantially horizontally disposed retracted position, and lock means on said transverse member for fixedly retaining said locking end of the leg in each of said leg positions. 2. The self-storing material handling attachment of claim 1 further including a plurality of locking pins individually retaining said slidably mounted leg members on the upright frame assembly, and at least one pivot pin mounting each pivotal leg member on the transverse member.

3. The self-storing material handling attachment of claim 2 wherein said locking pins associated with the slidable leg members are selectively employed to retain said legs in an extended and retracted position, and said pivot pins provide a fulcrum about which the pivotally mounted leg members assume their extended and retracted positions.

4. The self-storing material handling attachment of ,claim 1 wherein said slidable legs extend and retract in a substantially vertical direction, said legs further including a generally vertically oriented portion with a foot member depending therefrom, said vertically oriented portion defining a series of holes along the length thereof, an upright bracket affixed to said frame and shaped to slidably receive said leg portion therein, said bracket further defining at least one hole positioned to correspond with the holes on said leg portion one at a time, and a removable pin insertable in the bracket hole and any of said leg holes in alignment therewith for retaining said leg in the extended and retracted position.

5. A self-storing material handling attachment mountable on a transport vehicle comprising, material engaging means, frame means including an upright frame member for attachment directly to said transport vehicle, and a horizontally disposed transverse member rigidly supported on said frame member, said frame means supporting said engaging means and removably mounted on a transport vehicle, and support means including a multiplicity of leg members borne by said frame means for movement relative to the frame means between retracted positions permitting unrestricted operation of the vehicle and extended positions for supporting the attachment independently of the vehicle, wherein,

a least one of said leg members is slidably mounted on said upright frame member, and at least one of said leg members is pivotably mounted on said transverse member,

and wherein said pivotal legs include a lower surfaceengaging foot end, an upper locking end, and an extended intermediate portion connecting said ends, said intermediate portion further defining an elongated slot therethrough adjacent said locking end, a pin mounted in said frame and extending through said slot, power means borne by said frame pivotally connected to each said pivotal leg adjacent its locking end for swinging the leg about said pin between a substantially vertically disposed frame supporting position and a substantially horizontally disposed retracted position, and lock means on said transverse member for fixedly retaining said locking end of the leg in each of said leg positions.

6. The self-storing material handling attachment of claim 5 in which said lock means includes a pair of spaced upper and lower right angularly related notches in the frame for alternatively receiving said locking end of the leg, and a camming surface on the frame angularly extending between said notches against which said locking end of the leg is slidably guided during movement of the leg between its frame supporting and retracted positions. 

1. A self-storing material handling attachment mountable on a transport vehicle comprising, material engaging means, frame means including an upright frame member for attachment directly to said transport vehicle, and a horizontally disposed transverse member rigidly supported on said frame member, said transverse member of said frame means supporting said engaging means and said upright member being removably mounted on a transport vehicle, and support means including a multiplicity of leg members borne by said frame means for movement relative to the frame means between retracted positions permitting unrestricted operation of the vehicle and extended positions for supporting the attachment independently of the vehicle, wherein at least one of said leg members is slidably mounted on said upright frame member, and at least one of said leg members is pivotably mounted on said transverse member, and wherein said pivotal legs include a lower surface-engaging foot end, an upper locking end, and an extended intermediate portion connecting said ends, power means borne by said frame pivotally connected to each said pivotal leg adjacent its locking end for swinging the leg between a substantially vertically disposed frame supporting position and a substantially horizontally disposed retracted position, and lock means on said transverse member for fixedly retaining said locking end of the leg in each of said leg positions.
 2. The self-storing material handling attachment of claim 1 further including a plurality of locking pins individually retaining said slidably mounted leg members on the upright frame assembly, and at least one pivot pin mounting each pivotal leg member on the transverse member.
 3. The self-storing material handling attachment of claim 2 wherEin said locking pins associated with the slidable leg members are selectively employed to retain said legs in an extended and retracted position, and said pivot pins provide a fulcrum about which the pivotally mounted leg members assume their extended and retracted positions.
 4. The self-storing material handling attachment of claim 1 wherein said slidable legs extend and retract in a substantially vertical direction, said legs further including a generally vertically oriented portion with a foot member depending therefrom, said vertically oriented portion defining a series of holes along the length thereof, an upright bracket affixed to said frame and shaped to slidably receive said leg portion therein, said bracket further defining at least one hole positioned to correspond with the holes on said leg portion one at a time, and a removable pin insertable in the bracket hole and any of said leg holes in alignment therewith for retaining said leg in the extended and retracted position.
 5. A self-storing material handling attachment mountable on a transport vehicle comprising, material engaging means, frame means including an upright frame member for attachment directly to said transport vehicle, and a horizontally disposed transverse member rigidly supported on said frame member, said frame means supporting said engaging means and removably mounted on a transport vehicle, and support means including a multiplicity of leg members borne by said frame means for movement relative to the frame means between retracted positions permitting unrestricted operation of the vehicle and extended positions for supporting the attachment independently of the vehicle, wherein, a least one of said leg members is slidably mounted on said upright frame member, and at least one of said leg members is pivotably mounted on said transverse member, and wherein said pivotal legs include a lower surface-engaging foot end, an upper locking end, and an extended intermediate portion connecting said ends, said intermediate portion further defining an elongated slot therethrough adjacent said locking end, a pin mounted in said frame and extending through said slot, power means borne by said frame pivotally connected to each said pivotal leg adjacent its locking end for swinging the leg about said pin between a substantially vertically disposed frame supporting position and a substantially horizontally disposed retracted position, and lock means on said transverse member for fixedly retaining said locking end of the leg in each of said leg positions.
 6. The self-storing material handling attachment of claim 5 in which said lock means includes a pair of spaced upper and lower right angularly related notches in the frame for alternatively receiving said locking end of the leg, and a camming surface on the frame angularly extending between said notches against which said locking end of the leg is slidably guided during movement of the leg between its frame supporting and retracted positions. 